Skidders are used in the logging industry for transporting or sorting logs by pulling them along the ground. This is achieved by a grapple on the skidder which comprises a pair of opposed tongs which grips the log or logs for pulling along the ground. The tongs are pivotally mounted members which are hydraulically or cable operated for moving towards and away from one another in order to effect the gripping action. The grapple is located at the end of a boom which can be raised or lowered by hydraulic or cable means.
A grapple can be used to transport a bundle of logs in which case the grapple is used to clamp all the logs between the tongs, or it can be used in applications where single or smaller diameter logs are transported. A problem which arises in the latter type of application is that the tongs of some grapples do not come close enough together when closed in order to effectively grip a log. A further problem which arises is that grapples which are designed for gripping a bunch of logs, referred to as bunching grapples, have a relatively long opening and closing time making them very time consuming to open and close for a single log or broken tree.
It is accordingly an object of the present invention to alleviate the above difficulties.